The present invention relates to torque transmission and more particularly to an improved shaft coupling having a spherically-formed interface and engaging teeth to accommodate misalignment of interconnected shafts during transmission.
In power transmission systems, particularly aboard aircraft, the transfer of torque from a driving unit to an accessory component often requires use of an intermediate member to interconnect them and transfer rotary motion therebetween. Rigid one-piece members having external longitudinal splines have been used as torque couplers and generally perform well as long as alignment is maintained between the shafts of the driver and driven units. When misalignment of the shafts occurs, however, a severe load burden is placed on the drive unit resulting in costly problems of repair and replacement.
Existing splined couplings do not adequately resolve all of the problems caused in power transmission systems by the relative misalignment of shaft members. Although these couplings have generally been effective in reducing the load burden placed upon drive units when misalignment occurs, they have not been entirely satisfactory in reducing spline wear, a cause for expensive replacement and maintenance actions, particularly in the drive unit. Furthermore, existing concepts of flexible couplings have not had universal application in power transmission systems, but rather have been restricted by geometric and space limitations and torque requirements of the system.
Accordingly, a coupling that transmits torque unaffected by relative misalignment of interconnected shafts is of prime importance to effective operation of power transmission systems, and particularly, to aircraft operations and safety.